Threadless slide fastener chains

ABSTRACT

Slide fastener chains having a filamentary stringer with a plurality of head elements interconnected to a plurality of generally U-shaped heel members are formed by disposing stringers along a longitudinal edge of carrier tapes with the heel members threadlessly bonded with the carrier tape so that the filamentary stringers are firmly attached thereto.

Urnted States Patent 11 1 1111 3,885,274

Moertel May 27, 1975 [541 THREADLESS SLIDE FASTENER CHAINS 3.490.098 1/1970 Frohlica 241205.13 D

[7 Inventor: George M RD FOREIGN PATENTS 0 R APPLICATIONS Conneautvllle, 16406 709551 5/1965 Canada 24/211510 c 22 Filed: 10 1972 1,173,917 2/1960 France .1 24/205.l3 C 1,280,111 11/1961 France 24/20513 c [21] Appl. No: 225,146 1,229,600 4/1971 United Kingdom 1. 24/205.l3 C

Related U.S. Application Data I [63] Continuation-in-part of Ser. No. 64,487, Aug. 17. Pnmar" Exammer Bemdrd Geldk 1970, abandoned.

[57] ABSTRACT 24/205'16 C; Slide fastener chains having a filamentary stringer with 58 i 205 13 C a plurality of head elements interconnected to a plu- 1 0 earc 5 13 rality of generally U-shaped heel members are formed by disposing stringers along a longitudinal edge of carrier tapes with the heel memlbers threadlessly bonded [56] References cued with the carrier tape so that the filamentary stringers UNITED STATES PATENTS are firmly attached thereto. 2,497,821 2/1950 Kohler 24/205.16 c 3,063,120 11/1962 Steingrubner 24/20513 c 13 Claims, 6 Drawing Flgures THREADLESS SLIDE FASTENER CHAINS CROSS REFERENCE TO RELATED APPLICATIONS The present application is a continuation-in-part of my application Ser. No. 64,487 filed Aug. 17, 1970 and now abandoned.

BACKGROUND OF THE INVENTION 1. Field of the Invention:

The present invention pertains to slide fastener chains and more particularly to threadless slide fastener chains wherein the stringers are directly bonded with the carrier tapes.

2. Description of the Prior Art:

Numerous slide fasteners utilize coupling elements of the type formed from a continuous length of filamentary material which has been deformed into a series of head elements interconnected to first and second sets of generally U-shaped heel members by a plurality of legs. Such a continuous filamentary stringer is com monly referred to as a ladder-type stringer and may be manufactured from any suitable plastic material which, after being formed, can be conveniently attached to a carrier tape.

Generally, in manufacturing a slide fastener incorporating this type of stringer, the stringer is disposed with the head elements aligned next to a longitudinal edge of a carrier tape with the plurality of legs and the first and second sets of heel members overlying respective opposite surfaces of the tape. The plurality of legs of the filamentary stringer are thereafter attached to the carrier tape by suitable stitching or braiding which typically passes through the carrier tapes and around the exposed outer surface of each of the legs to securely affix the stringer to the tape in such a position that the protruding head elements from a pair of filamentary stringers may be easily interengaged for effectively joining a pair of carrier tapes. The resulting interengaged article, which is commonly referred to as slide fastener chain, is then processed through a series of subsequent operations to produce individual finished slide fasteners of a given size or length.

Slide fasteners of the type just described have proven to be highly satisfactory under various conditions of use and as a result have received widespread commercial acceptance. However, in a number of applications such slide fasteners are exposed to considerable surface abrasion on both inner and outer surfaces thereof which has a tendency to sever, tear or otherwise damage the exposed stitching threads. As can be readily appreciated, abrasion of the stitching threads tends to free the stringers from the tapes which often results in misalignment of the interengagable head elements and can cause the slide fastener to jam or to undesirably open at the point of thread wear.

The prior art, as exemplified by US. Pat. No. 3,054,364, is generally cognizant of various techniques for attaching filamentary stringers to carrier tapes; however, a practical and effective threadless slide fastener chain has not heretofore been available.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a method of manufacturing slide fastener chain without using threads to secure the stringer to the tape thereby producing an improved threadless slide fastener chain.

The present invention has a further object to provide a method of securely attaching heel members of a filamentary stringer to a carrier tape without stitching threads or braiding thus producing a threadless slide fastener chain.

Another object of the present invention is to ultrasonically fuse the heel members of a filamentary stringer with a carrier tape to form a threadless slide fastener chain.

The present invention has an additional object in the construction of a threadless slide fastener chain wherein portions of a carrier tape are displaced into the interstices of a filamentary stringer and are rigidly bonded thereto to form a chain with improved wear characteristics.

A further object of this invention is to attach a filamentary stringer to a carrier tape by bonding superimposed filamentary stringer portions to each other through a carrier tape.

The present invention is generally characterized in that a threadless slide fastener chain includes a carrier tape, a filamentary stringer having a plurality of head elements interconnected to a plurality of generally U- shaped upper and lower heel members by a plurality of legs, the filamentary stringer being disposed along a longitudinal edge of the carrier tape with the plurality of legs and the upper and lower heel members overlying respective opposite surfaces of the carrier tape, and each of the upper and lower heel members being threadlessly bonded with the carrier tape whereby the filamentary stringer is firmly attached to the carrier tape.

Some advantages of the present invention reside in its simplicity of construction, economy of manufacture and ability to withstand considerable surface abrasion without being damaged.

Other objects and advantages of the present invention will become apparent from the following description of the preferred embodiments taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a partial plan view of an embodiment of a threadless slide fastener chain. according to the present invention;

FIG. 2 is a partial sectional view taken on line 22 of FIG. 1;

FIG. 3 is a partial cross-section taken on line 3-3 of FIG. 1;

FIG. 4 is a partial plan view of a second embodiment of a threadless slide fastener chain according to the present invention;

FIG. 5 is a partial sectional. view taken online 55 of FIG. 4; and

FIG. 6 is a partial cross-section taken on line 66 of FIG. 4.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIGS. 1-3, the present invention is embodied in a threadless slide fastener chain, indicated generally at 10, having a pair of carrier tapes l2 and 13 upon which are disposed a respective one of a pair of filamentary stringers 14 and 15. The filamentary stringers 14 and 15 are substantially identical and are each preferably formed from a continuous length of plastic filamentary material which has been deformed into a series of head elements 16-17 interconnected to first and second sets of generally U-shaped heel members 18-19 and 20-21, respectively, by first and second sets of generally straight legs or leg portions 22-23 and 24-25, respectively. The filamentary stringers l4 and are each disposed along a longitudinal edge of one of carrier tapes 12 and 13 with the first and second sets of legs and the first and second sets of heel members overlying respective opposite sides or surfaces of the carrier tapes as illustrated in FIGS. 2 and 3. The stringers thus straddle the edge of the carrier tapes with the head elements 16 and 17 aligned in parallel relationship with such edge whereupon they may be easily interengaged as shown in FIG. 1.

The carrier tapes 12 and 13 are generally flat except at their inner longitudinal edges where they are each displaced upwardly and downwardly at spaced points along the edge to conform to the interstices defined by each of the U-shaped upper and lower heel members 18-19 and 20-21, respectively, and the straight legs 22-23 and 24-25. The edge of the carrier tape is thus convoluted or sinuous as can be visualized in FIG. 2 with each displaced portion of the tape forming an arcuate raised surface conforming precisely to the interstitial dimensions of the legs and heel members of the stringers.

It should be understood that the carrier tapes may take any number of forms depending upon the particular contemplated application of the finished slide fasteners. For example, such tapes may be woven or sewn flat and subsequently deformed, either prior to assembly with the stringers or concurrent therewith, or may be woven to assume its distorted edge shape without requiring a subsequent displacing step. The tapes may also be of the nonwoven type wherein the various fibers used therein are bonded or fused together to form flat strips of material in accordance with any number of well known manufacturing techniques.

Each of the filamentary stringers are attached to the carrier tape in its displaced shape by directly bonding the generally U-shaped heel members of the stringer to the arcuate raised surface of the carrier tape with the fused portion 26 being diagrammatically illustrated in the drawings. It can be seen that by directly bonding the stringers with the carrier tape, the slide fastener chain requires no stitching threads and is thus capable of withstanding considerable surface abrasion which would otherwise sever or tear the stitching employed in conventional slide fastener chains.

Such bonding may be accomplished by any of a number of techniques including, for example, the use of adhesives, dielectric heating, irradiation or ultrasonic fusing. If ultrasonic fusing, for example, is employed to produce the bond, the filamentary stringers as well as the carrier tapes are preferably constructed so as to contain a suitable thermoplastic or fusible material. The ultrasonic energy is thereafter directed through the U-shaped heel members of the stringer and the carrier tape such that a bond of sufficient strength will be formed at the area of contact between the tape and the stringer to assure positive attachment therebetween. It is noted that the strength of such bond is enhanced by the convoluted or arcuately raised surface of the tape which provides a relatively large surface area of contact between the tape and the heel members of the stringer. Furthermore, the raised surfaces of the tapes become rigidized during bonding whereupon the vertically displaced interstitial portions of the carrier tape act as abutments which tend to prevent separation of the tape from the stringer when subjected to lateral disruptive forces.

As mentioned above, the carrier tapes may be of any suitable type such as a nonwoven material. Such nonwoven carrier tapes have an inherently high degree of elasticity which makes them especially well suited for use in the threadless slide fastener chain according to the present invention. This is primarily due to the fact that the elasticity of the nonwoven tape permits the tape to deform somewhat under the force of a point load applied to one of the head elements of the stringer; as a result, the point load is distributed to adjacent elements whereupon it can be absorbed without causing damage to the slide fastener chain.

Referring now to FIGS. 4-6, there is illustrated a second embodiment of a threadless slide fastener chain according to the present invention. The threadless slide fastener chain of FIGS. 4-6 is similar to that of FIGS. 1-3 and identical numerals with added thereto will be used to describe correspondingly similar structure.

The threadless slide fastener chain of FIGS. 4-6 has a pair of initially substantially flat carrier tapes 1 12 and 113 upon which are disposed a respective one of a pair of filamentary stringers 114 and 115. The filamentary stringers 114 and 115 are substantially identical and are each preferably formed from a continuous length of plastic filamentary material which has been deformed into a series of head elements 116-117 interconnected to first and second sets of generally U- shaped heel members 118-119 and 120-121, respectively, by first and second sets of generally straight legs 122-123 and 124-125, respectively. The filamentary stringers 114 and 115 are each disposed along a longitudinal edge of one of carrier tapes 112 and 113 with the first and second sets of legs and the first and second sets of heel members overlying respective opposite surfaces of the carrier tapes as illustrated in FIGS. 5 and 6. The stringers thus straddle the edge of the carrier tapes with the head elements 116 and 117 aligned in parallel relationship with such edge whereupon they may be easily interengaged as shown in FIG. 4.

In the slide fastener chain illustrated in FIGS. 4-6, the carrier tapes 112 and 113 each define a set of spaced holes -131 therethrough which are aligned in parallel relationship with the longitudinal edge of the tape. Each of the holes are cut through the tape in such a position as to be interposed between an end of adjacent upper and lower heel members 118-119 and 120-121, respectively. The carrier tapes are initially not displaced or convoluted as in the preceeding embodiment but are generally flat throughout. The filamentary stringers are then placed on the tapes so as to straddle the perforated edge of the tape with the ends of the U-shaped heel members aligned with the holes. The heel members are thereafter held together with the ends of adjacent heel members in contact as illustrated in FIGS. 5 and 6 whereupon they are bonded together as by adhesives, ultrasonic fusing, etc., in a manner similar to that described with respect to the preceeding embodiment, with the fused portion 126 being diagrammatically illustrated in the drawings. In this manner, the ends of adjacent upper and lower heel members of the stringers are positively bonded or fused together such that the stringers are firmly attached to the carrier tapes without the use of stitching threads, braiding, or the like.

It should be noted that, as before, the particular carrier tape employed in the slide fastener chain of FIGS. 4-6 may be either woven or nonwoven and may or may not contain thermoplastic or other fibers depending upon the contemplated use of the finished slide fastener. The tapes are distorted, as in the previous embodiment, in order to provide a larger bonding surface between the stringers and tapes.

Thus, threadless slide fastener chains according to the present invention are simple in construction, are economical to manufacture, do not require the use of stitching threads, braiding, or the like, and effectively withstand a degree of surface abrasion which would otherwise produce undesired tearing of conventionally employed stitching threads and resultant premature failure thereof.

Inasmuch as the present invention is subject to many variations, modifications and changes in detail, it is intended that all matter contained in the foregoing description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

1. In a threadless slide fastener chain, the combination comprising a carrier tape,

a filamentary stringer having a plurality of head elements and a plurality of generally U-shaped heel members with leg portions interconnecting the plurality of head elements,

said filamentary stringer being disposed along a longitudinal edge of said carrier tape with a first set of the plurality of heel members on one side of the carrier tape and with a second set of the plurality of heel members on the other side of the carrier tape,

said filamentary stringer having first interstices between the leg portions of the first set of heel members and having second interstices between the leg portions of the second set of heel members,

said carrier tape adjacent the longitudinal edge being sinuous to form portions of the carrier tape projecting into the first interstices, and

said first and second sets of heel members being threadlessly bonded with said carrier tape such that the projecting portions of the carrier tape are retained in the first interstices.

2. The invention as recited in claim 1 wherein said carrier tape comprises a material containing thermoplastic fibers.

3. The invention as recited in claim 2 wherein said material is woven.

4. The invention as recited in claim 2 wherein said material is nonwoven.

5. The invention as recited in claim 2 wherein said filamentary stringer comprises a thermoplastic material, and wherein said first and second sets of heel members are fused with said carrier tape.

6. The invention as recited in claim 1 wherein said carrier tape is initially formed flat and subsequently deformed to assume its sinuous shape.

7. The invention as recited in claim 1 wherein said carrier tape is initially formed with one edge having its sinuous shape.

8. The invention as recited in claim 1 wherein said first and second sets of heel members are rigidly bonded to the projecting portions of said carrier tape.

9. The invention as recited in claim 6 wherein said 5 filamentary stringer comprises a thermoplastic material and said carrier tape comprises a material Containing thermoplastic fibers, and wherein said first and second sets of heel members are fused to the projecting portions of said carrier tape.

10. The invention as recited in claim 1 wherein the ends of adjacent heel members on the one and other sides of the carrier tape are bonded together through said carrier tape.

11. The invention as recited in claim 10 wherein said filamentary stringer comprises a thermoplastic material, and wherein the ends of adjacent heel members on the one and other sides of the carrier tape are fused together.

12. The invention as recited in claim 11 wherein said carrier tape comprises a material containing thermoplastic fibers, and wherein the ends of adjacent heel members on the one and other sides of the carrier tape are fused together by said carrier tape.

13. The invention as recited in claim 1 wherein said carrier tape defines a plurality of spaced holes therethough longitudinally aligned in parallel relationship with said longitudinal edge of said carrier tape, each of said holes being interposed between ends of adjacent heel members on the one and other sides of the carrier tape.

14. The invention as recited in claim 13 wherein the ends of said adjacent heel members are bonded together through said holes. I

15. The invention as recited in claim 14 wherein said filamentary stringer comprises a thermoplastic material and wherein ends of said adjacent heel members are fused together through said holes.

16. The invention as recited in claim 1 wherein said carrier tape adjacent the longitudinal edge is sinuous to form portions of the carrier tape projecting in opposite directions and into the respective first and second interstices.

17. The invention as recited in claim 1 wherein said carrier tape adjacent the longitudinal edge has first and second portions projecting into respective spaced first interstices and spaced second interstices, and

said filamentary stringer having interposed first interstices and interposed second interstices between the respective spaced first and second interstices free of projecting portions of the carrier tape.

18. In a threadless slide fastener chain, the combination comprising a carrier tape,

a filamentary stringer having a plurality of head elements and a plurality of generally U-shaped heel members with leg portions interconnecting the plurality of head elements,

said filamentary stringer being disposed along a longitudinal edge of the carrier tape with a first set of the plurality of heel members on one side of the carrier tape and with a second set of the plurality of heel members on the other side of the carrier tape,

said filamentary stringer having first interstices between the leg portions of the first set of heel mem- 7 8 bers and having second interstices between the leg carrier tape, and portions of the second set of heel members, said first and second sets of heel members being said carrier tape adjacent the longitudinal edge havthreadlessly bonded with the carrier tape such that ing portions projecting into spaced first interstices the projecting portions are retained in the spaced with interposed first interstices between the spaced first interstices.

first interstices free of projecting portions of the 

1. In a threadless slide fastener chain, the combination comprising a carrier tape, a filamentary stringer having a plurality of head elements and a plurality of generally U-shaped heel members with leg portions interconnecting the plurality of head elements, said filamentary stringer being disposed along a longitudinal edge of said carrier tape with a first set of the plurality of heel members on one side of the carrier tape and with a second set of the plurality of heel members on the other side of the carrier tape, said filamentary stringer having first intErstices between the leg portions of the first set of heel members and having second interstices between the leg portions of the second set of heel members, said carrier tape adjacent the longitudinal edge being sinuous to form portions of the carrier tape projecting into the first interstices, and said first and second sets of heel members being threadlessly bonded with said carrier tape such that the projecting portions of the carrier tape are retained in the first interstices.
 2. The invention as recited in claim 1 wherein said carrier tape comprises a material containing thermoplastic fibers.
 3. The invention as recited in claim 2 wherein said material is woven.
 4. The invention as recited in claim 2 wherein said material is nonwoven.
 5. The invention as recited in claim 2 wherein said filamentary stringer comprises a thermoplastic material, and wherein said first and second sets of heel members are fused with said carrier tape.
 6. The invention as recited in claim 1 wherein said carrier tape is initially formed flat and subsequently deformed to assume its sinuous shape.
 7. The invention as recited in claim 1 wherein said carrier tape is initially formed with one edge having its sinuous shape.
 8. The invention as recited in claim 1 wherein said first and second sets of heel members are rigidly bonded to the projecting portions of said carrier tape.
 9. The invention as recited in claim 6 wherein said filamentary stringer comprises a thermoplastic material and said carrier tape comprises a material containing thermoplastic fibers, and wherein said first and second sets of heel members are fused to the projecting portions of said carrier tape.
 10. The invention as recited in claim 1 wherein the ends of adjacent heel members on the one and other sides of the carrier tape are bonded together through said carrier tape.
 11. The invention as recited in claim 10 wherein said filamentary stringer comprises a thermoplastic material, and wherein the ends of adjacent heel members on the one and other sides of the carrier tape are fused together.
 12. The invention as recited in claim 11 wherein said carrier tape comprises a material containing thermoplastic fibers, and wherein the ends of adjacent heel members on the one and other sides of the carrier tape are fused together by said carrier tape.
 13. The invention as recited in claim 1 wherein said carrier tape defines a plurality of spaced holes therethough longitudinally aligned in parallel relationship with said longitudinal edge of said carrier tape, each of said holes being interposed between ends of adjacent heel members on the one and other sides of the carrier tape.
 14. The invention as recited in claim 13 wherein the ends of said adjacent heel members are bonded together through said holes.
 15. The invention as recited in claim 14 wherein said filamentary stringer comprises a thermoplastic material and wherein ends of said adjacent heel members are fused together through said holes.
 16. The invention as recited in claim 1 wherein said carrier tape adjacent the longitudinal edge is sinuous to form portions of the carrier tape projecting in opposite directions and into the respective first and second interstices.
 17. The invention as recited in claim 1 wherein said carrier tape adjacent the longitudinal edge has first and second portions projecting into respective spaced first interstices and spaced second interstices, and said filamentary stringer having interposed first interstices and interposed second interstices between the respective spaced first and second interstices free of projecting portions of the carrier tape.
 18. In a threadless slide fastener chain, the combination comprising a carrier tape, a filamentary stringer having a plurality of head elements and a plurality of generally U-shaped heel members with leg portions interconnecting the plurality of head elements, said filamentary stringer being disposed along a longitudinal eDge of the carrier tape with a first set of the plurality of heel members on one side of the carrier tape and with a second set of the plurality of heel members on the other side of the carrier tape, said filamentary stringer having first interstices between the leg portions of the first set of heel members and having second interstices between the leg portions of the second set of heel members, said carrier tape adjacent the longitudinal edge having portions projecting into spaced first interstices with interposed first interstices between the spaced first interstices free of projecting portions of the carrier tape, and said first and second sets of heel members being threadlessly bonded with the carrier tape such that the projecting portions are retained in the spaced first interstices. 